Question

Einstein's mass-energy equation is E=mc 2 , where mass is in kilograms and the speed of light is 3.00×108m/s. The unit of energy is the joule (4.184J=1cal;1000cal=1kcal,1J=1kg⋅m2/s2).

A. Calculate the energy released, in calories, when 5 g of matter is converted to energy.

Express your answer with the appropriate units.

B. Calculate the energy released, in kilocalories, when 5 g of matter is converted to energy.

Express your answer with the appropriate units.

C. A bowl of cornflakes supplies 110 kcal (110 food calories). How many bowls of cornflakes would supply the same amount of energy as you calculated for 5 g of matter in Part A?

Answer 1

Unit conversion is the key concept.